main{
    background: #fff;
}
.sitenav{
    padding: 0 50px;
    li{
        height: 30px;
        line-height: 30px;
        background: #f1f1f1;
        border: 1px solid #ccc;
        float: left;
        padding: 0 5px;
        margin: 5px;
        position:relative;
        a{
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
        }
        img{
            width: 16px;
            height: 16px;
           
        }
    }
}